Closure cap



June 6, 1967 D. o. ACTON 3,323,672

CLOSURE CAP Filad Feb. 11, 1.965

INVENTOR. Dam/a. 0L ficrm wimp/va United States Patent 3,323,672 CLOSURECAP Daniel D. Acton, Lancaster, Ohio, assignor to Anchor Hocking GlassCorporation, Lancaster, Ohio, :1 corporation of Delaware Filed Feb. 11,1965, Ser. No. 431,844 4 Claims. (Cl. 215--44) The present inventionrelates to the sealing art and more particularly to an improved closurecap and to a related container finish which cooperates with the cap toprovide an improved sealed package.

The closure cap is for sealing threaded or logged conminers and has aseries of concealed and inwardly projecting lugs at the lower edge ofthe cap skirt permitting the cap skirt itself to be relatively straightand smooth. This not only provides an attractive design form but alsopermits the skirt to be conveniently used for trademark andinstructional indicia as Well as for decorative designs. The cap has animproved tightly formed flexible lug which adapts the cap for acceptingthe tolerance extremes of closure cap, closure liner, and containerfinish. A preferred container thread finish cooperates with the cap lugsto eliminateabrasion and chippage of the finish thread.

While the lugs and thread finish of the present invention are usefulwith a variety of gaskets or liners, they are particularly effective foruse with safety seal liners. Safety seal liners have sealing membraneslightly adhered to inner cardboard cap liners. When the caps are appliedto the containers, the membranes are adhered to the container rims toform an air tight seal. As the caps are removed from the containers, themembranes remain glued to the container rims and the cap strips thecardboard liner from the sealing membrane and lifts it from the sealedpackage. The cap lug and container finish of this invention cooperate toaccommodate for the tolerance extremes in liner thicknesses in suchliners and provide a tight seal without lug damage or container threadabrasion or chippage.

Accordingly, an object of the present invention is to provide animproved closure cap.

Another object of the present invention is to provide an improved sealedpackage.

Another object of the present invention is to provide an improvedclosure cap having tightly formed and fleXible concealed lugs.

Another object of the present invention is to provide an improvedclosure cap having a safety seal liner.

Other and further objects of the invention will be obvious upon anunderstanding of the illustrative embodiment about to be described orwill be indicated in the appended claims, and various advantages notreferred to herein will occur to one skilled in the art upon employmentor" the invention in practice.

A preferred embodiment of the invention has been chosen for purposes ofillustration and description and is shown in the accompanying drawings,forming a part of the specification, wherein:

FIG. 1 is a perspective view partially in section of a preferredembodiment of the closure cap;

FIG. 2 is an enlarged fragmentary .sectional view of the closure cap ofFIG. 1 applied to a container having a preferred thread finish;

FIG. 3 is an enlarged detailed sectional view showing the preferredembodiments of the lug and thread finish;

FIG. 4 is a fragmentary elevational view of the inside of the cap skirtillustrating the shape of the improved lug; and

FIG. 5 is a fragmentary bottom plan view of the cap skirt illustratingthe shape of the lug.

The closure cap 1 in accordance with the present invention comprises acover 2 and depending skirt 3. As indicated above, the skirt 3preferably has a smooth surface to facilitate decoration and also toprovide a closure cap 1 with an attractive appearance. The cover 2 alsois relatively fiat facilitating decoration, however, as best illustratedin FIG. 2 a stacking panel 4 is provided on the cover by the formationof a circular channel 5 at the outer edge of the cap cover 2 adjacent tothe skirt 3. The outer edge of the channel 5 is defined by the topportion of the skirt 3and the inner edge is defined by an inclined wall6. The channel 5 and the stacking panel 4 are com veniently formedduring the drawing step when a fiat disc of the cap forming metal isdrawn into a cup-like blank.

The lower edge of the cap skirt 3 has an inwardly rolled head 7connecting a series of spaced container thread engaging lugs 8. As bestillustrated in FIGS. 3 thru 5, each of the lugs 8 includes an innercontainer thread engaging portion comprising a double thickness of thecap material formed into a tight fold 9. The lug 8 is formed to includean upwardly and inwardly inclined lower portion 10 extending to thethread engaging fold 9 which is positioned about centrally of the depthof the skirt head 7. The lugs 8 are formed as shown in FIG. 4 so thatthe fold 9 extends generally level or parallel to the lower edge of theskirt 3 and with the level fold 9 comprising a substantial portion ofthe circumferential length of each lug. As illustrated in FIG. 5 whichis a bottom plan view of a lug '8, the lugs 8 are seen to extendradially inwardly for a substantial distance along a major portion oftheir circumferential length with the fold 9 having a slightly arcuateshape when viewed in this direction.

The logs 8 of the closure cap 1 engage a series of inclined threads 11on a container 12. A preferred cross section of the threads '11 isillustrated wherein the folds 9 of the lugs 8 engage the lower surfaces13 of the threads. The lower surfaces 13 in cross section are upwardlyand outwardly inclined and are relatively straight intermediate theircurved end portions.

The cap 1 of the present invention is particularly useful with capshaving paperboard liners and particularly those having safety seal[liners of the well-known type wherein an air-tight membrane 14 is usedto seal the container mouth. As seen in FIG. 2, this membrane 14 ispreferably initially and lightly attached to a paperboard liner 15 ofsufiicient thickness to be relatively stiff. The liners 15 and theattached membranes 14 are placed in the finished closures 1 prior to thesealing operation and the cap lugs -8 retain the liners 15 and sealingmembranes 14 in position during the cap handling and sealing operations.

In order to insure a tight initial seal and the retention of the sealduring packaging handling and storage, it is desirable that the edge ofthe stacking panel 4 of the cap top be above at least a portion of thecontainer rim 16 so that it engages the liner 15 during and after thesealing operation as illustrated in FIG. 2. In order to obtain thisresult, the channel 5 forming the stacking panel 4 is preferablyrelatively narrow and a preferred channel positions the inner edge 6 ofthe channel so that it is approximately above the inner edge of the caplugs 8 as seen in FIG. 2. As described above it is preferable that thesealing membrane 14 and liner 15 extend radially outwardly to a positionover lugs 8 to insure the retention of the liners 15 within the capsbefore and during sealing and also to insure that the cap lugs 8 removethe paperboard liner portions 15 when the closure caps 1 are removedfrom the sealed containers 12 thus insuring that the paperboard liners15 are stripped clear of the package sealing membranes 14.

It will be seen that an improved closure cap has been provided combiningthe advantages of a. tightly formed, flexible, concealed in lug and asmooth, straight skirt. This combination of features provides a capuniquely suited for packaging products heretofore commonly packagedusing caps of the continuous thread type and having irregular skirtsurfaces. The cap has a novel lug structure formed by a related novellug forming process wherein concealed lugs are provided with the abilityto accept the extremes of closure, liner, and container finishtolerances. A container finish thread is provided which cooperates withthe novel lug to eliminate abrasion and chippage of the container finishthread. The capability of the lug and package to accept extremes ofliner thickness tolerances makes the cap particularly suitable for usewith paperboard liners including those used with safety seal membranes.Consistently air-tight seals are obtained using such safety seal linerswith the improved cap.

As various changes may be made in the form, construction and arrangementof the parts herein without departing from the spirit and scope of theinvention and without sacrificing any of its advantages, it is to beunderstood that all matter herein is to be interpreted as illustrativeand not in a limiting sense.

Having thus described my invention, I claim:

1. In a closure cap for sealing a container and having a cover and adepending skirt with an inwardly rolled bead at the lower edge of theskirt and a plurality of circumferentially spaced lugs projectinginwardly therefrom the improvement which comprises an outwardly directedtight fold at the inner edge of each lug extending along a minor portiononly of the radial width of the lug, and

the folded edges of the lug lying in a common plane generally parallelto the plane of the cap cover and being spaced upwardly from thelowermost portions of said head.

2. The closure cap as claimed in claim 1 which further comprises adownwardly facing channel at the outer portion of said cap cover forminga stacking panel and having its inner wall positioned above the foldededges of said lugs.

3. The closure cap as claimed in claim 1 which further comprises a cutcap liner extending radially outwardly beyond the inner edges of saidlugs.

4. The closure cap as claimed in claim 1 which further comprises a cutcap liner in said cap having an air impervious membrane on its surfaceopposite to the cap cover for engaging the container.

References Cited UNITED STATES PATENTS 1,684,415 8/1928 Schriver 215442,089,954 8/1937 Gibbs 2l544 2,148,169 2/1939 Merolle 21544 3,134,4965/1964 Kehe 215-40 JOSEPH R. LECLAIR, Primary Examiner.

GEORGE O. RALSTON, Examiner.

R. PESHOCK, Assistant Examiner.

1. IN A CLOSURE CAP FOR SEALING A CONTAINER AND HAVING A COVER AND A DEPENDING SKIRT WITH AN INWARDLY ROLLED BEAD AT THE LOWER EDGE OF THE SKIRT AND A PLURALITY OF CIRCUMFERENTIALLY SPACED LUGS PROJECTING INWARDLY THEREFROM THE IMPROVEMENT WHICH COMPRISES AN OUTWARDLY DIRECTED TIGHT FOLD AT THE INNER EDGE OF EACH LUG EXTENDING ALONG A MINOR PORTION ONLY OF THE RADIAL WIDTH OF THE LUG, AND THE FOLDED EDGES OF THE LUG LYING IN A COMMON PLANE GENERALLY PARALLEL TO THE PLANE OF THE CAP COVER AND BEING SPACED UPWARDLY FROM THE LOWERMOST PORTIONS OF SAID BEAD. 